This is a request for purchase of an electron microscope which would be the central item of equipment in a new core facility for electro microscopy at Cornell University Medical College. The instrument, which will be under the joint supervision of the Departments of Anatomy and Physiology, will be housed in the Department of Anatomy together with other equipment and facilities required for electron microscopy. It will be serviced and maintained by a full-time technician, who will be available to teach inexperienced investigators in the use of the microscope or to perform microscopy on a fee-for-service basis.